JP5135543B2 - Coke oven riser dust collection method - Google Patents

Description

  The present invention relates to a dust collection method for a coke oven riser pipe.

  FIG. 3 is a partial sectional view showing an outline of the coke oven. In the coke oven, coal is loaded into a coal loading vehicle 5 that reciprocates on the furnace, coal is charged from a plurality of inlets 2 disposed in the upper part of the carbonizing chamber 1, and a charged coal layer 7 is formed in the carbonizing chamber 1. Let The charged coal layer 7 in the carbonization chamber 1 is dry-distilled over 10 hours by indirect heating through the furnace wall brick from the adjacent combustion chamber. Gas generated during dry distillation is recovered by the riser 4. After completion of dry distillation, coke is extruded out of the furnace with an extruder 6 to produce coke.

  At this time, carbon generated by the thermal decomposition of the coke oven gas generated during the dry distillation of coal adheres to the inner wall of the coking chamber 1 of the coke oven and the inner wall of the charging port 2 and the rising pipe 4 depending on the operating rate of the furnace. The adhering carbon has a useful function of tightly sealing the brick joints. On the other hand, it can grow if left untouched, leading to clogging of the extruder 6, and inhibiting gas recovery. Causes dry distillation failure. Therefore, in order to prevent the above-described adverse effects, it is necessary to periodically remove carbon.

  As a method for removing the adhering carbon, high pressure gas is blown to the base of the rising pipe 5 to separate and remove, or a lance is inserted from the inlet 2 and the like, and an oxygen-containing gas is introduced into the furnace to remove it by combustion. The method is adopted. At this time, a large amount of dust is entrained and scattered from the upper part of the ascending pipe 4 by the superheated air, which may deteriorate the working environment and pollute the atmosphere. Therefore, from the viewpoint of environmental protection, in order to suppress the excessive growth of carbon, the operation rate is lowered, for example, the furnace temperature is lowered.

On the other hand, as a method for operating without lowering the operating rate, measures for collecting dust discharged from the coke oven riser 4 are also taken. As a method, the structure of the ascending pipe 4 is greatly modified, and after cleaning and collecting dust by applying high-pressure water to the dust-containing gas passing through the ascending pipe 4 with a nozzle installed at the bottom of the canopy provided with a dish valve A method for releasing into the atmosphere has been proposed (Patent Document 1).
JP 07-258647 A

In general, a coke oven is composed of several tens of furnaces in one furnace group, and has one riser 4 for each furnace. In order to remodel the structure of several tens to several hundred ascending pipes 4 as in the technique described in Patent Document 1, a huge capital investment is required. Also, since at least 0.5 liters of water per 1 m ³ of processing gas is required to perform cleaning and dust collection, it is necessary to clean and collect thousands of m ^{3 of} gas generated during the carbon removal operation. Requires a huge amount of water. Since the amount of water is enormous in order to store water with the tray valve closed as in the technique described in Patent Document 1, a separate large wastewater treatment facility is required.

  Furthermore, in the technique disclosed in Patent Document 1, all the removed dust is accumulated inside the dry main. Many carbon adhering to the base of the ascending pipe 4 is in the form of a lump, and if they accumulate inside the dry main, the problem is that the flow path of the dry main is blocked and the pressure loss increases and the gas recovery rate decreases. There is.

  On the other hand, dust that has fallen around the furnace once it has not been removed, or dust that has leaked from places other than the riser 4, such as the kiln opening, and dropped around the furnace, can be rolled up again in the weather and scattered into the atmosphere. There is sex. In order to solve these problems, deposits are mainly moistened by watering, but the watering range is vast and it is necessary to install watering nozzles at several locations. There is a problem that it costs maintenance.

  The problem to be solved by the present invention is to provide a dust collection method for coke oven riser exhaust gas that can efficiently collect dust-containing gas discharged from the coke oven riser with little capital investment.

As a result of repeated studies by the present inventors, when cleaning dust collection, the dust-containing gas discharged from the coke oven riser pipe is collected efficiently by a multi-layer spray layer having different droplet diameters. The inventors have found that dust collection can be performed, and have completed the present invention. That is, the gist of the present invention is as follows.
( 1 ) A method for collecting dust from a coke oven riser exhaust gas, in which the atomized liquid is jetted to the upper part of the riser pipe with respect to the dust-containing gas discharged from the coke oven riser pipe. to form different multi-spray layer with droplet diameter, in the spray layer of the multilayer, to said the droplet size of the spray layer located above is smaller than the droplet diameter of the sprayed layer located below Turkey Dust collection method for the exhaust gas from the riser furnace.

  The present invention can efficiently collect the dust-containing gas discharged from the coke oven riser pipe with the minimum equipment modification without performing a large-scale equipment modification. Further, since the dust accumulated around the furnace is wetted, it is possible to prevent the dust accumulated around the furnace from being scattered.

  The dust-containing gas discharged from the coke oven riser pipe, which is the target of dust collection of the present invention, is a gas containing carbon dust discharged by the operation of the carbon removing means, and the carbon removing means is not limited. For example, there are carbon lances for removing carbon adhering to the furnace wall, riser base scarfing for removing carbon adhering to the riser base, ceiling scarfing for removing carbon adhering to the furnace ceiling, etc. it can.

  The dust collection method of the present invention is to collect dust by jetting atomized liquid to the upper part of the riser pipe with respect to the dust-containing gas discharged from the coke oven riser pipe, and the jetted atomized liquid group Are characterized by forming a multi-layer spray layer having different droplet diameters. By using a multilayer spray layer with different droplet diameters, particles with different particle diameters can be collected more efficiently, and dust collection efficiency can be increased.

  On the other hand, you may inject so that the injected atomization liquid may be mixed and may inject as a single layer which improved the space filling rate of atomization liquid. When the particle size distribution of the dust in the exhaust gas is in a narrow range, a single layer may be used instead of a multilayer.

  The droplet diameter of the ejected liquid depends on the particle size of the target dust and the distance from the nozzle to the riser 4, but the average droplet diameter is 50 times or more the particle size of the target dust particle size. What is necessary is just to spray so that it may become the droplet diameter of this, and what is necessary is just to inject so that the atomized liquid injected at that time may form the multilayer spray layer from which a droplet diameter differs.

  When forming a multi-layer spray layer, the droplet diameter of the upper spray layer is made smaller than the droplet diameter of the lower spray layer to collect relatively coarse particles with the large lower layer droplets. The fine particles that have passed through the lower layer are collected by small droplets in the upper layer.

  The spray layer may be a multilayer of two or more layers, but sufficient dust collection efficiency can be obtained with two layers. When forming two spray layers, the droplet diameter of the upper spray layer is selected 50 times the minimum particle size of the target dust, and the droplet size of the lower spray layer is appropriately selected within the range of 50 times the maximum particle size of the target dust. do it.

  Similarly, when the number of layers is three or more, the droplet diameter of the spray layer positioned above may be smaller than the droplet diameter of the spray layer positioned below. However, if the fine liquid droplets that are trapped by strong winds and so on do not reach the upper part of the riser, which is the target point, the uppermost layer and the lowermost layer may be large droplets, and the fine droplets between them may be used. .

  Examples of the liquid to be sprayed include water, a chemical solution such as a surfactant, an ionized solution to which an electric force is applied, and the like. The most inexpensive water is preferable.

  The position for injecting the liquid is the upper part of the riser 4 where the dust-containing gas is discharged. What is necessary is just to select an injection angle suitably in the range without specification.

The spraying of the liquid may be performed at a flow rate of about 0.5 liter to 4 liters per 1 m ³ of the processing gas.

  The sprayed liquid collects dust at the upper part of the riser and then drops it around the furnace. The excess water of the sprayed liquid is used to wet the dust accumulated around the furnace and suppress secondary scattering. The ascending pipes are installed continuously at intervals of about 1 m to 1.5 m, and by spraying all the ascending pipes, fine and wide-range watering is possible.

The dust dropped around the furnace together with the excess water is collected using a cleaning vehicle or the like. Generally, in a coke oven, a cleaning system is in place, so dust that has fallen on the ground can be recovered relatively easily.
As a result, it is possible to avoid large-scale capital investment such as watering equipment around the furnace and water treatment equipment.

  The means for spraying the liquid is not particularly limited, but the liquid may be sprayed using a nozzle. The arrangement of the nozzles for forming two spray layers is shown in FIG.

  The nozzles 31 and 32 having different droplet diameters may be arranged in a staggered manner so that two spray layers are formed. In this case, the droplet diameter that forms the upper spray layer is a liquid that forms the lower spray layer. What is necessary is just to arrange | position the nozzles 31 and 32 from which a nozzle diameter differs so that it may become smaller than a droplet diameter.

  One embodiment of the method of the present invention is shown in FIG. The nozzle 3 for sprinkling may be installed in the charcoal vehicle 5. It is preferable to install the water storage tank, the compressor, etc. on the charcoal vehicle 5 that moves on the furnace or on the platform to which the charcoal vehicle 5 pulls. In the operation of the coke oven, the interval between the kiln to be loaded and the kiln to be pushed out is constant. Therefore, the liquid injection equipment is installed at a position in consideration of the interval between the kilns on the charcoal vehicle 5 or a frame pulled by the charcoal vehicle. As a result, water can be sprinkled on the upper part of the riser 4 without installing a large-scale watering facility on the furnace.

  The present invention was carried out in a coke 3 furnace. Since the target dust particle diameter was 10 to 20 μm, the average droplet diameter of the lower layer was set to 1000 μm, and the average droplet diameter of the upper layer was set to 500 μm. The average droplet diameter is calculated from the equation (1).

  The collected water was collected, and the dust collection efficiency was calculated from the amount of dust contained in the collected water and the amount of generated dust. As a comparison, when the upper and lower nozzles were changed, the dust collection efficiency when the average droplet diameter was changed was measured. The results are shown in Tables 1 and 2. As shown in Tables 1 and 2, it was confirmed that high dust collection efficiency can be obtained by the present invention.

  The present invention is extremely useful because dust-containing gas discharged from the coke oven riser can be efficiently collected with a small capital investment.

Explanatory drawing of the arrangement | positioning of the nozzle for forming the two spraying layer from which a droplet diameter differs. Explanatory drawing which shows one Embodiment of the method of this invention. The fragmentary sectional view which shows a coke oven.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbonization chamber 2 Charging inlet 3, 31, 32 Sprinkling nozzle 4 Rising pipe 5 Charcoal wheel 6 Extrusion ram 7 Charging layer 8 Spraying layer

Claims (1)

A method for collecting dust from a coke oven riser exhaust gas, in which the atomized liquid is jetted to the upper part of the riser tube with respect to the dust-containing gas discharged from the coke oven riser tube. different multilayer to form a spray layer, in a spray layer of the multilayer, features and to Turkey Kusu furnace is smaller than the droplet diameter of the sprayed layer that droplet size of the spray layer is positioned below positioned above rise in Dust collection method for pipe exhaust gas.